[CLIENT] Mastery page naming

If you try renaming a mastery page with the same name as an already existing, the page number gets appended in (). http://i.imgur.com/q0hRZJu.png If you however use different capitalisation on the text it passes the check and bugs out after that without renaming the page. http://i.imgur.com/2MNfFjm.png

If I update the LCU I'll test it on there aswell, but if anyone's interested they're welcome to do it.